Title
Maternal and infant serum carotenoids are associated with infantile
atopic dermatitis development
To the Editor,
Various epidemiological studies have shown that eczema/atopic dermatitis
(AD) in infancy is a risk for skin sensitization1 and
development of allergic diseases later in life2.
Carotenoids are natural pigments biosynthesized by bacteria, fungi, and
plants, but not by mammals3; thus, they need to be
supplied via dietary intake of vegetables and fruits or certain animal
products. Carotenoids positively impact human health and prevents
allergic reactions via their provitamin A activity and high antioxidant
potential. However, previous studies using food frequency questionnaires
that evaluated the association between maternal vegetable intake during
pregnancy and eczema in offspring have shown inconsistent
results4–6. As these studies did not measure the
levels of individual carotenoids in the serum of mothers or children and
in breast milk, appropriate nutritional interventions in maternal and
early infant intake of vegetables for the prevention of AD remain
unclear.
In this study, we have measured the levels of total carotenoids and some
of their sub-types in the serum of mothers and children and in maternal
breast milk, to evaluate the association between carotenoid levels and
the presence of AD at 1 year of age in
infants.
We compared participants’ characteristics and exposures by 1 year of age
(Table S1); carotenoid, retinol, and α-tocopherol levels (Table 1) in
the serum of participants, with and without AD at 1 year of age, were
compared to those in the serum and breast milk of their respective
mothers. We found that both the presence of eczema (OR, 31.7;
95%CI[13.2–76.0]) and S. aureus carriage in the skin by 6
months of age (OR, 5.20; 95%CI[2.30–11.75]) were associated with
higher odds of AD development at 1 year of age. On the contrary, certain
carotenoid levels in the serum and breast milk, including total
carotenoids in the maternal blood, were associated with lower odds of AD
at 1 year.
To avoid multicollinearity in the regression analysis, we selected seven
relevant predictive variables among the carotenoid data using VIP scores
in the PLS analysis (Table S2). Stepwise logistic regression analysis
using explanatory baseline characteristics, exposure by 1 year of age,
and the seven selected carotenoid levels revealed that the following
variables were significantly related to AD at 1 year of age (Table 2):
presence of eczema by 6 months of age (OR, 34.5; P <
0.0001), maternal blood lutein level (unit OR, 0.002; P = 0.002),
and infant blood lycopene level at 1 year (unit OR, 0.01; P =
0.007).
One strength of this study is that multiple biological sample types were
used as proxies for carotenoid intake. The lutein concentration in the
maternal blood at 36 weeks of gestation, which was associated with a
reduced AD risk at 1 year of age in the multivariate analysis, was
significantly correlated with the cord blood lutein level (Table S3).
This suggests that lutein ingested during pregnancy is transferred to
the fetus and may have an inhibitory effect on the development of AD in
infancy. Another strength of this study is that multiple carotenoids
were evaluated simultaneously; the concentrations of lutein, zeaxanthin,
α-carotene, β-carotene, and lycopene were strongly correlated,
suggesting that these nutrients are absorbed together (Table S4).
In conclusion, the results of this study suggest that children of
mothers with low carotenoid intake during pregnancy are at higher risk
for developing infantile AD and are ideal targets for early intervention
in allergy prevention. Further studies are needed to clarify whether
carotenoid supplementation during pregnancy/in lactating mothers and
infants after weaning has a preventive effect on AD development in
infancy.
Table 1 Levels of each carotenoid, total carotenoids, retinol,
and α-tocopherol in each type of sample in participants with or without
atopic dermatitis at 1 year of age